In general, horn speakers are known as speakers that emit sound from a diaphragm into an external space through a horn. Although horn speakers are more efficient than directly emitting speakers and can control the directionality of the sound through the horn shape, the reproduction range of sound is relatively narrow, and they are mainly used as speakers for mid- to high-range sound. In addition, the speaker causes the diaphragm to vibrate with an electrical frequency, and the sound from vibration of the diaphragm is transmitted through the air. The wavelength of the sound hit by the air spreads in the desired direction through the speaker's horn or affects the sound volume. This horn speaker is constituted by an electroacoustic conversion unit. It is a piezoelectric horn speaker if the diaphragm of the electroacoustic conversion unit is vibrated by a piezoelectric element; and it is a dynamic horn speaker if the diaphragm is vibrated by a voice coil, which is vibrated by electromagnetic force.
Such speaker devices have a structure for reproducing the voice by converting, into vibration of the vibration member, the voice signal current reproduced by sound signal generators such as audio equipment, public address (PA) equipment for broadcasting, and sirens. For such speaker devices, development of a structure for faithful restoration of the original sound is actively being carried out.
The traditional speaker device described above is shown in prior art Korean Patent Application No. 10-2009-0088885. In considering such traditional speaker, as shown in FIGS. 1 and 2, a radial horn speaker (1) is comprised of a cabinet (10), a duct (20), a speaker unit (30) and a horn part (40). In such configuration, the rear panel (13) of the cabinet is generally coupled to one side of the cabinet body (11) in such a way that the sound emitted from the baffle furnished in the speaker unit (30) is delivered to the front of the cabinet body (11), and a coupling step (13a) is formed at a predetermined height on one side of the cabinet rear plate (13) to fasten the cabinet rear plate (13) to the inside (12) of the cabinet body (11). The duct (20) is coupled to a surface (23) of the opposite side of the cabinet body (11). The body of the speaker unit (30) is passed through a central opening (22) in the duct (20) and is positioned within the inside (12) of the cabinet body (11). The rim of the diaphragm housing of speaker unit (30) is set on the annular base of the horn (40), which is coupled to an exterior end face of the duct (20). As such, the cabinet (10) is coupled to the cabinet rear plate (13) through a plurality of retaining pins to prevent it from breaking away when the duct (20) is fastened. Accordingly, the cabinet rear plate (13) plays a role of helping the output of the sound produced from the speaker unit (30) according to the sound occurred due to the baffle (not shown) being emitted between the horn (40) and the duct (20) that is coupled to the speaker unit (30).
However, according to the prior art structural feature, it has a structure of the horn (40) and the duct (20) being coupled in one direction. Here, the efficiency of the speaker is improved as the length of the horn (40) becomes longer, given that its conformity to the air is improved accordingly. However, since the horn (40) is installed in a separate duct (20) for the conventional structure, it limits the size and length of the horn (40) and reduces the efficiency of the speaker unit (30). Also, it is difficult to perform multiple sound reproduction, by classifying the sound of multiple bands with one speaker unit (30). In addition, since the source sound of the speaker unit (30) is emitted only through the discharge outlet of the horn installed in the front direction, there is an issue wherein diffusion of the source sound is not smoothly transmitted towards the rear.